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Fluxes Footprint and Source Area of Rubber Plantation 被引量:1
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作者 吴志祥 谢贵水 +3 位作者 陈帮乾 杨川 周兆德 陶忠良 《Agricultural Science & Technology》 CAS 2011年第12期1937-1942,共6页
[Objective] The paper was to analyze the quality of flux observation data of rubber plantation.[Method]Based on the FSAM model,footprint and flux source area were analyzed according to the continuous flux measurement ... [Objective] The paper was to analyze the quality of flux observation data of rubber plantation.[Method]Based on the FSAM model,footprint and flux source area were analyzed according to the continuous flux measurement with the open-path eddy covariance system on the 50 m tower of Danzhou Key Field Station of Observation and Research for Tropical Agricultural Resources and Environments,Ministry of Agriculture from Jan 1 to Jun 30,2010.[Result] Under unstable stratification,source areas were smaller than those under stable conditions,and source areas in the dormant season were larger than those in the growing season at the same level.In the main wind direction 130°-270°,the upwind range of source areas was in the magnitude of 100-758 m and vertical upwind range was-251-251 m at 80% level under unstable stratification in the growing season,and they were some large than those under the unstable stratification in the dormant season.The source areas of the upwind and vertical upwind ranges were 173-1 858,-534-534 m especially under stable stratification in the growing season,and they were smaller than those under stable stratification in the dormant season.In the other wind directions of 0°-130° and 270°-360°,the ranges were similar to those of the growing season in the prevailing wind direction under the same atmospheric conditions.[Conclusion] The study would lay a foundation for the future flux calculation and analysis. 展开更多
关键词 Flux footprint FSAM(the Flux-Source area Model) Flux source area Rubber plantation(forest) Hainan Island
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Critical area computation for real defects and arbitrary conductor shapes 被引量:2
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作者 王俊平 郝跃 《Chinese Physics B》 SCIE EI CAS CSCD 2006年第7期1621-1630,共10页
In current critical area models, it is generally assumed the defect outlines are circular and the conductors to be rectangle or the merger of rectangles. However, real defects and conductors associated with optimal la... In current critical area models, it is generally assumed the defect outlines are circular and the conductors to be rectangle or the merger of rectangles. However, real defects and conductors associated with optimal layout design exhibit a great variety of shapes. Based on mathematical morphology, a new critical area model is presented, which can be used to estimate the critical area of short circuit, open circuit and pinhole. Based on the new model, the efficient validity check algorithms are explored to extract critical areas of short circuit, open circuit and pinhole from layouts. The results of experiment on an approximate layout of 4 × 4 shifts register show that the new model predicts the critical areas accurately. These results suggest that the proposed model and algorithm could provide new approaches for yield prediction. 展开更多
关键词 real defects critical area model mathematical morphology yield estimation
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The “Valley Economy” Model of Regional Development: A Case Study of Mountain Areas in Beijing, Northern China 被引量:5
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作者 LIU Chun-la CHEN Ming-xing +3 位作者 TANG Zhi-peng LIU Wei-dong LU Da-dao ZHANG Yi-feng 《Journal of Mountain Science》 SCIE CSCD 2014年第5期1372-1382,共11页
A case study is presented of a regional development model for valley economies in the mountain areas of Beijing, China. The nature and framework of the valley economy model are described and the development of the mod... A case study is presented of a regional development model for valley economies in the mountain areas of Beijing, China. The nature and framework of the valley economy model are described and the development of the model, which is specific to the mountain areas of Beijing, is analyzed. Five different valley economy models applied in the Beijing mountain areas are compared. The major purpose of the valley economy model is to develop the regional economy, including the selection of appropriate industries, the allocation of industrial space, the establishment of supply chains and the integration of various industries. Pilot experiments using the valley economy model have been conducted in seven counties(districts) in Beijing: Pinggu, Huairou, Changping, Mentougou, and Fangshan districts, and Yanqing and Miyun counties. Five models for developing the Beijing mountain areas have been explored, including: creative cultural industries, characteristic industry clusters, the promotion of large tourist areas, natural scenic tourism and folk cultural tourism. Each model has its own unique features and potential to help in the regional development of mountain areas. 展开更多
关键词 Beijing Mountainous areas Regional development Valley economy model
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Time function of surface subsidence based on Harris model in mined-out area 被引量:7
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作者 Liu Xinrong Wang Junbao +2 位作者 Guo Jianqiang Yuan Hong Li Peng 《International Journal of Mining Science and Technology》 SCIE EI 2013年第2期251-254,共4页
The surface subsidence is a common environmental hazard in mined-out area. Based on careful analysis of the regularity of surface subsidence in mined-out area, we proposed a new time function based on Harris curve mod... The surface subsidence is a common environmental hazard in mined-out area. Based on careful analysis of the regularity of surface subsidence in mined-out area, we proposed a new time function based on Harris curve model in consideration of the shortage of current surface subsidence time functions. By analyzing the characteristics of the new time function, we found that it could meet the dynamic process, the velocity change process and the acceleration change process during surface subsidence. Then its rationality had been verified through project cases. The results show that the proposed time function model can give a good reflection of the regularity of surface subsidence in mined-out area and can accurately predict surface subsidence. And the prediction data of the model are a little greater than measured data on condition of proper measured data quantity, which is safety in the engineering. This model provides a new method for the analysis of surface subsidence in mined-out area and reference for future prediction, and it is valuable to engineering application. 展开更多
关键词 Mined-out area Surface subsidence Time function Harris model Prediction
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IAP General Circulation Models: A First Step Towards Developing a Local Area Model for Weather Prediction in Nigeria
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作者 李伟平 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 1999年第1期121-134,共14页
In an earlier study, the Atmospheric Models Intercomparison Program (AMIP) simulations of African climate using the nine-layer gridpoint atmospheric general circulation model were found to be closely related to the ob... In an earlier study, the Atmospheric Models Intercomparison Program (AMIP) simulations of African climate using the nine-layer gridpoint atmospheric general circulation model were found to be closely related to the observed European Centre for Medium Range Weather Forecast (ECMWF) temperature data at 500 and 850 hPa. This paper presents the analysis of the simulation of African climate using the Global Ocean-Atmosphere-Land System Model (IAP/LASG GOALS) and the nine-layer spectral general circulation model rhomboidally truncated at zonal wave number 15 (L9R15) developed at the Institute of Atmospheric Physics (IAP), Chinese Academy of Sciences, Beijing. Both model simulations were not significantly different from the National Center for Environmental Prediction (NCEP) Reanalysis monthly mean data for 1980-1995 in the case of surface air temperature, sea level pressure and precipitation, with the GOALS reproducing the seasonal mean climate over Africa better. The implications of the encouraging results in developing a local area model for Nigeria have been discussed. The great role of topography in the developing of general circulation models for numerical modelling of weather and climate has been stressed. 展开更多
关键词 General circulation models Reanalysis data Simulations Local area model
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Simulating deforestation of Nepal by area production model
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作者 肖映秋 魏丽娟 周荣俊 《Journal of Forestry Research》 SCIE CAS CSCD 2001年第1期47-50,共5页
Based on the growth rates of population, Gross Domestic Products (GDP) and agriculture productivity, the areas of deforestation were predicted in Jutp ani village, Chitwan district, Nepal by Area Production Model (AP... Based on the growth rates of population, Gross Domestic Products (GDP) and agriculture productivity, the areas of deforestation were predicted in Jutp ani village, Chitwan district, Nepal by Area Production Model (APM). Through the APM simulation in this study, all of forestland will be transferred into agricu ltural land in 2030 at the rate of 24% per year on the current productivity. And if the productivity of subsistence food crop is assumed to increase at the rate of 1%, the productivity of market crop and export crop increase at the rate of 2% annually, deforestation rate will decrease to 17% per year, but only 124 hm2 forest land will be left till 2038. The agriculture productivity is a very impor tant factor for the deforestation, so intensification of agriculture management is more important. 展开更多
关键词 area Production Model (APM) Simulation deforestation Gross Domestic Products (GDP) Subsistence food crop Market food crop
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Estimating Poverty in Greece in Small Geographical Areas
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作者 Stefanos G. Giakoumatos Malapani Eleni 《Journal of Statistical Science and Application》 2017年第1期16-29,共14页
In this paper, the Small Area methods are presented. We use this method to produce estimates of poverty in Greece, at county (NUTS3) level. This is succeeded by combining survey data from EU-SILC 2013 with auxiliary... In this paper, the Small Area methods are presented. We use this method to produce estimates of poverty in Greece, at county (NUTS3) level. This is succeeded by combining survey data from EU-SILC 2013 with auxiliary data derived from the 2011 Census. In the application section, we adopt the Fay and Herriot model and we provide estimates for the percentage of Greek population under the poverty line in 2013 and also the mean equivalized income. Using Fay and Herriot model the percentages of poverty and the mean equivalized income changed in several areas. Also, the standard deviations of the estimates were improved in all prefectures. 展开更多
关键词 Small area model EBLUP Fay and Herriot model POVERTY EU-SILC CENSUS
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A Three-dimensional IP-based Telecom Metropolitan Area Network Model
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作者 Li Hongbiao (Data Division of ZTE Corporation, Nanjing 210012, China) 《ZTE Communications》 2005年第3期52-55,共4页
The Metropolitan Area Network (MAN) has faced serious problems after years of rapid development. The model of three-dimensional IP-based MAN, proposed by ZTE, is a next-generation MAN solution, which not only solves t... The Metropolitan Area Network (MAN) has faced serious problems after years of rapid development. The model of three-dimensional IP-based MAN, proposed by ZTE, is a next-generation MAN solution, which not only solves the existing problems but also brings new ideas for the development of next-generation MAN. 展开更多
关键词 IP A Three-dimensional IP-based Telecom Metropolitan area Network Model ZTE MPLS
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The Positive Research of Human Capital Structure and the Disparity Problem of Area in Our Country
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作者 Hailing Xu Xiumin Li Min Li 《Chinese Business Review》 2005年第7期41-48,共8页
The factors that influence the economic growth are various and complicated.This paper has especially probed into calculating and impact on regional economic growth of the human capital structure. First, on the basis o... The factors that influence the economic growth are various and complicated.This paper has especially probed into calculating and impact on regional economic growth of the human capital structure. First, on the basis of considering human capital quality, we use Gini coefficient law to calculate human capital structure coefficient of our country's each province (municipal or district); Second, according to the result of calculating of human capital structure coefficient, considering input of material capital, average education level and so on at the same time, we set up regional economic growth model and use the panel data to examine the model. The result indicates the human capital structure coefficient of each province (municipal or district)in inverse proportion to economic growth (- 0. 108). The last is the conclusion of this text. 展开更多
关键词 human capital structure coefficient the disparity problem of area panel data model
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Yield estimation of metallic layers in integrated circuits 被引量:2
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作者 王俊平 郝跃 张俊明 《Chinese Physics B》 SCIE EI CAS CSCD 2007年第6期1796-1805,共10页
In the existing models of estimating the yield and critical area, the defect outline is usually assumed to be circular, but the observed real defect outlines are irregular in shape. In this paper, estimation of the yi... In the existing models of estimating the yield and critical area, the defect outline is usually assumed to be circular, but the observed real defect outlines are irregular in shape. In this paper, estimation of the yield and critical area is made using the Monte Carlo technique and the relationship between the errors of yield estimated by circular defect and the rectangle degree of the defect is analysed. The rectangular model of a real defect is presented, and the yield model is provided correspondingly. The models take into account an outline similar to that of an original defect, the characteristics of two-dimensional distribution of defects, the feature of a layout routing, and the character of yield estimation. In order to make the models practicable, the critical area computations related to rectangular defect and regular (vertical or horizontal) routing are discussed. The critical areas associated with rectangular defect and non- regular routing are developed also, based on the mathematical morphology. The experimental results show that the new yield model may predict the yield caused by real defects more accurately than the circular model. It is significant that the yield is accurately estimated using the proposed model for IC metals. 展开更多
关键词 real defects critical area model mathematical morphology yield estimation
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Analysis and prediction of fishtail during V-H hot rolling process 被引量:5
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作者 李旭 王鸿雨 +2 位作者 丁敬国 徐久晶 张殿华 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第4期1184-1190,共7页
The fishtail in head and tail of the slabs was studied during V-H hot rolling process. With the application of ANSYS/LS-DYNA, simulation analysis was used to research this process. The various factors which have a gre... The fishtail in head and tail of the slabs was studied during V-H hot rolling process. With the application of ANSYS/LS-DYNA, simulation analysis was used to research this process. The various factors which have a great influence on fishtail shapes were analysed, such as initial width, initial thickness, radius of the edger roll and horizontal roll, edging draught,horizontal reduction rate, and friction coefficient of the surface. Then the curves that can describe the shapes were obtained. After a certain time of self-learning, the optimized curves were given out. At last, through the fitting of the simulation test results, the math models for the area of fishtail defect changing with the presented factors were received. The experimental results show that the accuracy of the prediction for the fishtail shapes is more than 95%. With the application of the prediction for the fishtail shapes and the area of the fishtail defect, the loss rate of the slab is decreased by about 0.1%. 展开更多
关键词 fishtail finite element defect area mathematical modeling
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Mapping Spatial Distribution Characteristics of Lineaments Extracted from Remote Sensing Image Using Fractal and Multifractal Models 被引量:7
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作者 Cheng Lyu Qiuming Cheng +1 位作者 Renguang Zuo Xueping Wang 《Journal of Earth Science》 SCIE CAS CSCD 2017年第3期507-515,共9页
Mapping mineral prospectivity in vegetated areas is a challenge. For this reason, we aimed to map spatial distribution characteristics of linear structures detected in remote sensing images using fractal and multifrac... Mapping mineral prospectivity in vegetated areas is a challenge. For this reason, we aimed to map spatial distribution characteristics of linear structures detected in remote sensing images using fractal and multifractal models. The selected study area was the Pinghe District of the Fujian Province(China), located in the Shanghang-Yunxiao polymetallic and alunite ore belt(within the Wuyishan polymetallic belt), where mineral resources such as copper, molybdenum, gold, silver, iron, lead, zinc, alunite and pyrophyllite have been discovered. The results of our study showed that:(1) the values of fractal dimension for all lineaments, NW-trending lineaments, and NE-trending lineaments, are 1.36, 1.32, and 1.23, respectively, indicating that these lineaments are statistically self-similar;(2) the fractal dimensions of the spatial distribution of the linear structures in the four selected hydrothermal-type ore deposits of the Pinghe District, named Zhongteng, Panchi, Xiaofanshan and Fanshan, are 1.43, 1.52, 1.37 and 1.37, respectively, which are higher than the mean value in South China;(3) the spatial distribution of the linear structures extracted from the remote sensing image and displayed by the contour map of fractal dimensions, correlates well with the known hydrothermal ore deposits; and(4) the results of the anomaly map decomposed by the spectrum-area(S-A) multifractal model is much better than the original fractal dimension contour map, which showed most of the known hydrothermal-type deposits occur in the high anomalous area. It is suggested that a high step tendency possibly matches with the boundary of the volcanic edifice and the deep fault controlling the development of the rock mass and the volcanic edifice. The complexity of the spatial distribution of mapped lineations(faults) in the Pinghe District, characterized by high values in the anomaly map, may be associated with the hydrothermal polymetallic ore mineralization in the study area. 展开更多
关键词 fractal model ETM+ data vegetation coverage area Pinghe molybdenum deposit
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An Assessment of a Nowcast/Forecast System for the Straits of Florida/Florida Current Regime
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作者 Christopher N.K.Mooers Inkweon Bang 《Journal of Ocean University of China》 SCIE CAS 2005年第4期288-292,共5页
The Florida Current (FC) largely fills the Straits of Florida and is variable on a broad spectrum of time and space scales. Some portions of the variability are due to variable forcing by tides, winds, heating/cooli... The Florida Current (FC) largely fills the Straits of Florida and is variable on a broad spectrum of time and space scales. Some portions of the variability are due to variable forcing by tides, winds, heating/cooling, and throughflow; other portions are due to intrinsic instabilities of the FC. To predict, as well as to better understand this complex regime, a nowcast/forecast system (East Florida Shelf Information System (EFSIS)) has been implemented and assessed (http://efsis. rsmas. miami. edu). EFSIS is based on an implementation of the Princeton Ocean Model (POM) with mesoscale-admitting resolution on a curvilinear grid. It is forced by a mesoscale numerical weather prediction system (called Eta) run operationally by the National Centers for Environmental Prediction (NCEP), eight tidal constituents from a global tidal model, and lateral boundary conditions from an operational global ocean prediction model, i.e., the Navy Coastal Ocean Model (NCOM). Real-time observations of coastal sea level, coastal sea surface temperature, coastal HF radar-derived surface current maps, and FC volume transport are used to verify and validate EFSIS. EFSIS is part of an evolving strategy for real-time predictive coastal ocean modeling methodology, and for fostering the understanding of the variability of the regime on several time and space scales. Here, some of the verification and validation results are provided, as well as diagnostic analyses of dynamical processes. The central point is that an example is provided of a 'scientific revolution' in progress that combines real-time observations and numerical circulation models to yield a credible sequence of synoptic views of coastal ocean circulation for the first time. 展开更多
关键词 ocean circulation circulation modeling nowcast/forecast system Florida Current mesoscale ocean variabili ty mesoscale atmospheric forcing tidal forcing limited area model
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Using Impervious Surfaces to Detect Urban Expansion in Beijing of China in 2000s 被引量:14
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作者 PENG Jian LIU Yanxu +3 位作者 SHEN Hong XIE Pan HU Xiaoxu WANG Yanglin 《Chinese Geographical Science》 SCIE CSCD 2016年第2期229-243,共15页
The change of impervious surface area(ISA) can effectively reveal the gradual process of urbanization and act as a key index for monitoring urban expansion. Experiencing rapid growth of the built environment in the 20... The change of impervious surface area(ISA) can effectively reveal the gradual process of urbanization and act as a key index for monitoring urban expansion. Experiencing rapid growth of the built environment in the 2000 s, urban expansion of Beijing has not been fully characterized through ISA. In this study, Landsat TM images of Beijing in 2001 and 2009 were obtained, and the eight-year urban expansion process in Beijing was analyzed using the ISA extracted by means of the vegetation-imperious surface-soil(V-I-S) model. From the spatial variation in ISA, the ring structure of urban expansion in Beijing was significant during the study period, with decreasing urban density from the city center to the periphery. In the ring road analysis, the most dramatic changes of ISA were found between the fifth ring and the sixth ring. This area has experienced the most new residential development, and is currently the main source of urban expansion. The typical profile lines revealed the directional characteristics of urban expansion. The east-west profile was the most urbanized axes in Beijing, while ISA change in the east-north profile was more significant than in the other five profiles. Moreover, the transition matrix of ISA levels revealed an increase in urban density in the low density built areas; the Moran′s I index showed a clear expansion of the central urban area, which spread contiguously; and the standard deviational ellipse indicated the northeast was the dominant direction of urban expansion. These findings can provide important spatial control guidelines in the next round of national economic and social development planning, overall urban and rural planning, and land use planning. 展开更多
关键词 impervious surface area(ISA) vegetation-imperious surface-soil(V-I-S) model profile line analysis urban expansion direction Beijing China
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Expansion of traditional land-use and deforestation:a case study of an adat forest in the Kandilo Subwatershed,East Kalimantan,Indonesia
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作者 Hunggul Y.S.H.Nugroho Anne van der Veen +1 位作者 Andrew K.Skidmore Yousif A.Hussin 《Journal of Forestry Research》 SCIE CAS CSCD 2018年第2期488-506,共19页
Deforestation issues are more problematic when indigenous(adat) communities,living within a forest,have lived there for many generations.These adat communities,who employ traditional land-use,are frequently accused of... Deforestation issues are more problematic when indigenous(adat) communities,living within a forest,have lived there for many generations.These adat communities,who employ traditional land-use,are frequently accused of encroaching on the forest.To understand existing and future trends in the spatial patterns of the expansion of traditional land-use and deforestation,we conducted a case study in the Kandilo Subwatershed using mixed methods with image interpretation,spatial modelling and sociocultural surveys to examine the interrelationships between physical conditions,community characteristics and traditional land-use expansion.We investigated community characteristics through household interviews,communication with key informants,and discussions with focusgroups.By using an area production model,we were able to analyze the effect of improved farming systems,policy intervention and law enforcement on traditional land-use expansion and deforestation.Based on our examination of a 20-year period of traditional land-use activities in adat forests,the evidence indicated that the steeper the slope of the land and the farther the distance from the village,the lower the rate of deforestation.Our study found that customary law,regulating traditional land-use,played an important role in controlling deforestation and land degradation.We conclude that the integration of land allocation,improved farming practices and enforcement of customary law are effective measures to improve traditional land productivity while avoiding deforestation and land degradation. 展开更多
关键词 Adat people Agriculture expansion area production model(APM) Customary law DEFORESTATION Traditional land-use
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On differences between deterministic and statistical models of the interphase region
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作者 Tomasz Wacławczyk 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2022年第8期73-88,共16页
This paper reviews differences between the deterministic(sharp and diffuse)and statistical models of the interphase region between the two-phases.In the literature this region is usually referred to as the(macroscopic... This paper reviews differences between the deterministic(sharp and diffuse)and statistical models of the interphase region between the two-phases.In the literature this region is usually referred to as the(macroscopic)interface.Therein,the mesoscopic interface that is defined at the molecular level and agitated by the thermal fluctuations is found with nonzero probability.For this reason,in this work,the interphase region is called the mesoscopic intermittency/transition region.To this purpose,the first part of the present work gives the rationale for introduction of the mesoscopic intermittency region statistical model.It is argued that classical(deterministic)sharp and diffuse models do not explain the experimental and numerical results presented in the literature.Afterwards,it is elucidated that a statistical model of the mesoscopic intermittency region(SMIR)combines existing sharp and diffuse models into a single coherent framework and explains published experimental and numerical results.In the second part of the present paper,the SMIR is used for the first time to predict equilibrium and nonequilibrium two-phase flow in the numerical simulation.To this goal,a two-dimensional rising gas bubble is studied;obtained numerical results are used as a basis to discuss differences between the deterministic and statistical models showing the statistical description has a potential to account for the physical phenomena not previously considered in the computer simulations. 展开更多
关键词 Multiphase flow Phase field and level-set methods area density model Statistical interface model Nonequilibrium phenomena in two-phase flow
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The Study of Chamber Rockburst by the CUSP Model of Catastrophe Theory 被引量:4
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作者 潘一山 章梦涛 李国臻 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 1994年第10期943-951,共9页
By means of CUSP model of catastrophe theory. this paper has studied thephysics process of rockburst occured on circular chamber. The present paper has nolonly described the instability process of rockburst more deepl... By means of CUSP model of catastrophe theory. this paper has studied thephysics process of rockburst occured on circular chamber. The present paper has nolonly described the instability process of rockburst more deeply. but also got the crilicaldepth of plastic softening area of chamber that is valuable in the controlling engineering of rockburst. the chamber displacement jump and energy liberation have been derived. the influence of rock parameters on the rockburst has been discussed . 展开更多
关键词 rockburst. CUSP model of catastrophe theory. critical depth ofplastic softening area. displacement jump. energy liberation
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The Meteorological Prediction Model of Lemon Production in Anyue County Based on Correlation
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作者 Chen Haiyan Xiao Tiangui +2 位作者 Cai Guanghui Liu Yaxi Chen Xuedong 《Meteorological and Environmental Research》 CAS 2014年第11期52-55,共4页
Using the meteorological data during 1971- 2013 and lemon growth and yield data during 2003- 2013 in Anyue,the suitability problem of lemon growth and correlation problem between meteorological factors and lemon growt... Using the meteorological data during 1971- 2013 and lemon growth and yield data during 2003- 2013 in Anyue,the suitability problem of lemon growth and correlation problem between meteorological factors and lemon growth in Anyue area were studied. According to relevance between the selected meteorological factors and yield of lemon,meteorological prediction model of lemon yield was established in Anyue,and the prediction accuracy was higher. The research had certain guiding significance for management work of lemon production in Anyue area. 展开更多
关键词 Lemon production Meteorological prediction model Correlation Anyue area China
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A modified simulated annealing algorithm and an excessive area model for floorplanning using fixed-outline constraints 被引量:5
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作者 De-xuan ZOU Gai-ge WANG +1 位作者 Gai PAN Hong-wei QI 《Frontiers of Information Technology & Electronic Engineering》 SCIE EI CSCD 2016年第11期1228-1244,共17页
Outline-free floorplanning focuses on area and wirelength reductions, which are usually meaningless, since they can hardly satisfy modern design requirements. We concentrate on a more difficult and useful issue, fixed... Outline-free floorplanning focuses on area and wirelength reductions, which are usually meaningless, since they can hardly satisfy modern design requirements. We concentrate on a more difficult and useful issue, fixed-outline floorplanning. This issue imposes fixed-outline constraints on the outline-free floorplanning, making the physical design more interesting and challenging. The contributions of this paper are primarily twofold. First, a modified simulated annealing(MSA) algorithm is proposed. In the beginning of the evolutionary process, a new attenuation formula is used to decrease the temperature slowly, to enhance MSA's global searching capacity. After a period of time, the traditional attenuation formula is employed to decrease the temperature rapidly, to maintain MSA's local searching capacity. Second, an excessive area model is designed to guide MSA to find feasible solutions readily. This can save much time for refining feasible solutions. Additionally, B*-tree representation is known as a very useful method for characterizing floorplanning. Therefore, it is employed to perform a perturbing operation for MSA. Finally, six groups of benchmark instances with different dead spaces and aspect ratios—circuits n10, n30, n50, n100, n200, and n300—are chosen to demonstrate the efficiency of our proposed method on fixed-outline floorplanning. Compared to several existing methods, the proposed method is more efficient in obtaining desirable objective function values associated with the chip area, wirelength, and fixed-outline constraints. 展开更多
关键词 Fixed-outline floorplanning Modified simulated annealing algorithm Global search Excessive area model B*-tree representation
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BGMM: A Body Gauss-Markov Based Mobility Model for Body Area Networks 被引量:5
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作者 Yi Liu Danpu Liu Guangxin Yue 《Tsinghua Science and Technology》 SCIE EI CAS CSCD 2018年第3期277-287,共11页
Existing mobility models have limitations in their ability to simulate the movement of Wireless Body Area Network(WBAN) since body nodes do not exactly follow either classic mobility models or human contact distribu... Existing mobility models have limitations in their ability to simulate the movement of Wireless Body Area Network(WBAN) since body nodes do not exactly follow either classic mobility models or human contact distributions. In this paper, we propose a new mobility model called Body Gauss–Markov Mobility(BGMM) model,which is oriented specially to WBAN. First, we present the random Gauss-Markov mobility model as the most suitable theoretical basis for developing our new model, as its movement pattern can reveal real human body movements. Next, we examine the transfer of human movement states and derive a simplified mathematical Human Mobility Model(HMM). We then construct the BGMM model by combining the RGMM and HMM models. Finally,we simulate the traces of the new mobility model. We use four direct metrics in our proposed mobility model to evaluate its performance. The simulation results show that the proposed BGMM model performs with respect to the direct mobility metrics and can effectively represent a general WBAN-nodes movement pattern. 展开更多
关键词 mobility metric mobility model human movement model random Gauss-Markov Wireless Body area Network(WBAN)
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